A conventional hearing aid or listening device includes a microphone that receives acoustic sound waves and converts the acoustic sound waves to an audio signal. That audio signal is then processed (e.g., amplified) and sent to the receiver of the hearing aid or listening device. The receiver then converts the processed signal to an acoustic signal that is broadcast toward the eardrum.
The broadcasting of the acoustic signal causes the receiver to vibrate. The vibrations can affect the overall performance of the listening device. For example, the vibrations in the receiver can be transmitted back to the microphone, causing unwanted feedback. Consequently, it is desirable to reduce the amount of vibrations that occur in the receiver of the hearing aid or listening device.
In one known prior art system, a pair of elastomeric sleeves are placed on the ends of the receiver. Each of the sleeves includes four distinct projections that engage the surrounding structure within which the receiver is placed. The eight projections are located adjacent to the eight corners of the receiver. The amount of dampening that is provided by the projections, however, is dependent on the material of the projections and also the relative amount of engagement force between each of the eight projections and the adjacent portions of the surrounding structure. Additionally, because the vibration pattern on the housing of the receiver varies depending on the distance from the acoustic output port, having eight similar projections at each corner may provide too much dampening at one position and not enough dampening at another position.
Other prior art techniques use foam tape to attach the receiver to the inside of the hearing aid structure or a rubber boot-like structure that is similar to the aforementioned prior art device. Again, it is very difficult to control the amount of dampening in these prior art suspension systems because the amount of dampening is dependent on the material properties and the exact location where contact is being made with the surrounding structure is not precisely known.